Front opening unified pod or front opening universal pod systems used in handling semiconductor wafers are commonly referred to as FOUPs. A FOUP is typically formed of a specialized plastic enclosure which is designed to hold semiconductor wafers securely and safely in a protective environment. A FOUP includes a front opening section which allows the wafers to be inserted therein and removed therefrom for processing. The semiconductor wafers are typically stored and transported within a FOUP by robotic handling systems. Each FOUP is designed to hold a particular sized wafer. For example, 300 millimeter semiconductor wafers are transported and stored in 300 millimeter sized FOUPs. And, 450 millimeter semiconductor wafers are stored and handled in 450 millimeter FOUPs. Robotic handling systems are used to handle FOUPs. A robotic tool typically secures an end effector which transports a particular sized FOUP. The FOUP is then placed onto a shelf which receives that particular sized FOUP. Shelves and end effectors used to handle a 300 millimeter FOUP are neither configured or capable of handling a 450 millimeter FOUP. Conversely, an end effector and shelf which handles a 450 millimeter size FOUP is not useable to handle a 350 millimeter FOUP. Accordingly, different size shelves and end effectors have been used to handle (including receiving and storing) different size FOUPs.
Accordingly, a need exists for a system for separately handling different size FOUPs so that the same end effector and shelf can be used to separately handle each of different size FOUPS. For example, the system should be able to separately handle a 300 millimeter FOUP and a 450 millimeter FOUP.